In DOS go to the directory that 'hello.java' is in and then type in 'javac hello.java' and try it, or is 'hello.java' already in the same directory as 'javac'? If it is, then I don't know what your problem could be.

The first line just goes into the directory that has Map.java. The second entry is compiling the file. The third command actually runs the program, and I didn't show the output because it fills up a screen. So that's what you need to do.

so this is what i did. i created a folder called java to store my programs. i did the "hello world" program and saved it as hello.java. i went to dos and typed in C:\>cd java and it said invalid directory. then i put the program in the bin folder and did C:\>cd j2sdk1.4.1_02\bin and it said invalid directory. then i did C:\>cd java \bin and so on and still got the same invalid directory. should i put C:\>cd java\hello or C:\>cd j2sdk1.4.1_02\bin\hello to do that?

Um, your problem isn't with Java then. It's using the command line... so what exactly are you typing? Can you copy the text for us? Just highlight everything and hit enter, and it's copied. Then paste it in your response.

Store all of your projects ( class file and your source code ) that you are working on presently in a folder at C:\Java and then store everything that you have completed in a folder labeled C:\Java Projects.

This is what I do and it makes it much easier to work with so when you go into DOS all you have to do is change your path to "C:\j2sdk1.4.0_03" and change your directory to C:\Java ( type "cd c:\Java" at your command prompt without the quotation marks )